Step 3: Build the generator

Step 4: Put it all together and test it out

Once you have a satisfactory generator setup, then you want to connect the generator to the charge circuit, insert the battery, and use your multimete...

Are you breathing? Do you have a gadget that can be charged via a USB port? Well if you answered yes to both, then you are in luck. This instructable shows how to make a device that will charge your USB-capable devices while you do what you do best. Breathe. Using some parts scavenged from an old CD-ROM drive, a simple electronic circuit, and a few rubber bands you will soon be huffing and puffing your way to fully-charged pseudo-useful electronic gadget nirvana.

Step 1: Introduction and Step 1

This project requires a wide range of "maker" skills, such as PCB board manufacture, dismantling of electronics, cutting and drilling plastics, mixing epoxy, designing a gear train, kludging together a bunch of parts, bending paper clips, and risking the well being of your ever so expensive phone, camera, or PDA. All in all, good fun.

Since everyone will have a different collection of junk parts to build this from, I will just give you a detailed overview of how I went about it and you can apply these ramblings to your own project. Which will consist loosely of four steps.

1. Scrounge up some suitable parts for the generator2. Build the charger circuit3. Assemble the generator, thorax coupler, and mechanical return4. Connect the charger circuit, and test

Step 1:

I had about four old CDROM drives hanging around and took apart a few of them to see what cool parts were inside. Turns out there are lots of cool motors, gears, and other parts inside that fully validate my insistence of keeping such crap laying around. Seeing the gear trains inside these units used for opening the tray gave me the idea for this project. The small low-torque, high-RPM motor is linked to the tray via a gear train that has a final ratio of about 20:1 Previously I had been using a parallel array of tiny pager motors to generate electricity from breathing (see below) but the linear travel from your chest expansion is not that great (around an inch) so in order to generate useful voltages you had to really huff and puff.

Anyway, tear into those CDROM drives, which you can find at pretty much any garage sale, thrift store, or landfill. The pic below shows the results. Lots of potential projects in there. For now, we are only interested in the plastic gears and the motors for opening the tray and/or moving the laser carriage.

Look over the various gears and drives and try to visualize a way to add additional gears to increase the gear ratio, or how to add another motor in series. You want to minimize the changes to the gear train. Alternatively you can just scavenge all the gears and build your gearbox up from scratch.

You are also going to need at least one motor with a small gear or pulley on it so that you can connect it to the gear train. The motors in the CDROM drive are typically simple permanent magnet DC motors designed to run on 5V, except for the spindle motor, which you don't want to use anyway.

At this point you also want to think about what you are going to use for a strap to go around your chest. An old belt, some webbing, an old shoelace, a name badge strap, or anything that will fit around you comfortably without any stretch to it. You want all the expansion to take place in your linear generator. Any stretch that occurs in your thorax coupler will be wasted energy.

What if you made this thing more durable so that, while you sleep, you can charge your phone overnight? This, in combination with some solar cells on your back, and that shoe-mounted generator, would make jogging look like a daily routine to just charge your phone! Although the solar cells on your back is kinda off since who would want to carry solar cells on their sweaty backs? I'll consider making this if I have the time.

Actually, there's this interesting little hat I found on my vacation to Singapore. It had solar panels on the top, and that was connected to a little fan pointed at your face. It's a self-regulating system, more sun = more power = faster fan, less sun = less power = slower fan. But I guess a little hand-crank thing is better at charging than this, since this is just a little experiment; nothing is meant for practicality.

How about nanosolar? And it's more of an "umbrella" than a real umbrella with all the fluid motion and whatnot. But yeah, I do agree that they would have to come off. How about NASA style? A single stack of panels that unfolds into a disk. To make portable, just make it do another 360 in reverse, clip 'em together, then fold down. I'll make an animation sometime this week. For now, I have to deal with a hacker and remotely mock his hacking skills halfway around the world.

A flywheel would be cool. It would add to the complexity, but since a custom gear train is in order anyway it wouldn't be too hard to pull off. The higher gear train ratios become tougher and tougher to build as the precision and strength of the gears gets more important with such a large ratio. The internal losses with a kludged together gear train at 100:1 would be considerable.

now you only have to downsize the concept and implement iut not only for breathing but for every cloth that involves the stretching of parts of the human body. You know how some people use weights to train for sports or any other resistance? Instead of this energy could be won out of it (for example by jogging one can power the own mp3 player). One only has to think of where motion or a difference appears - and energy can be sucked out of that.

About that PowerPoint-presentation you linked to:The idea of using electroactive polymer is interesting, have you looked more into it?Are such materials exotic and hard to make use of for a DIY'er?

I imagined piezoelectric materials was a good choice for non-conventional generators, however the info. in the PowerPoint-presentation says electroactive polymer is a better choice.Do you know approximately how many amps. a spark from a piezoelectric crystal produce? (Voltage can be in thousands.)

Both piezo and electroactive are tough to use in such a low frequency application. They both are more of a high voltage, low current source which means high impedance and complicates harvesting from this kind of bio source. MIT made a piezo shoe, but the efficiency is really poor. Since this is a waste source of energy, as in otherwise the work done on the shoe sole is turned into heat, efficiency is less of an issue. However, using the chest wall expansion of breathing is not a waste source and any extra effort required due to inefficient conversion is then a metabolic load on the wearer. Not ideal unless you are looking to lose weight while charging your phone.

I've got a concept for an improved device that I have been working on. I don't know if it will make an appearance on Instructables though. THanks for reading.

Also you can put a electrlytic capacitor to make a constant voltage, 470uf will work fine, conected in parallel with vcc and negative. Just breath a couple of times before you conect a charge. Saludos (:

A friend of mine is an industrial design major working on a project for school. She's looking to use this device in a unique application, but we're on some stringent time constraints. Neither of us have much experience with this sort of thing. If we buy the MintyBoost chip that you mentioned below as being similar, it does not have an input for the generator. How would we tie in the generator? Any help would be much appreciated.

See the schematic of the minty boost linked below. You'd need to add a full bridge rectifier between pin 6 of IC1 and GND, with the generator across the other two nodes. In my schematic, the rectifier is the array of 4 diodes (D1, D2, D3, D4). You'll need to duplicate my arrangement, with the generator outputs (PWN-IN in my schematic) across two nodes of the rectifier and the Vin (Pin 6 of IC1) and Gnd (Pin 1 of IC1) from the minty boost across the other two.

Another thing to note is that the minty boost may not even work without two batteries for baseline since the LT1302 IC is designed for 2V operation while the ST L6920 in my circuit operates down to 0.6V Also, based on the datasheets, the minty boost IC is 82% efficient at 2.4V input and my circuit's IC is 90% at 2.4V (84% at 1.2V input). Not a big deal.

The circuit is pretty similar to the main circuit in a Minty Boost if I recall correctly. You can buy a minty boost kit somewhere on teh Internets.

http://www.ladyada.net/make/mintyboost/

Otherwise, the cost of the components for my circuit is negligible, like less than $10. I can dig around and see if I can scrounge a complete board. Honestly I got sidetracked from this project and haven't looked at it in years so I can't be sure I even have any of it still. If I do, it would be better that someone use it than it sit in a drawer in my basement so I would be willing to donate to a good cause. What is your plan for the circuit?

science project. i'm a freshman in high school. i've been working on this project all year on ways to charge everyday devices using alternative energy sources. the breath powered usb charger is one of my main examples. it would be great if i could demonstrate it but i'm having problems making it on my own and my teacher's not much help :)

sos i'm from Peru ( latin america) if I cant get the lets call it ""memory " whit what I can replaced it maybe with i dont kow what kind of resistance !!!!??? thanks plis answer as soon as posible please!!!